ALGOL (Beta Persei) is the second brightest star of the Perseus constellation. To the eye, this class B (B8) star appears rather normal, its slightly bluish white light radiating from a surface with a temperature of 12,500 K. Like the Sun, it is a main sequence dwarf star fusing hydrogen in its core, though it is 3.5 times more massive. However, steady observation reveals a surprise. As regular as clockwork, every 2.867... days, the brightness of the star plummets to 30 percent of normal and back, the whole event (including recovery) taking only a few hours.
Algol has 7 planets orbiting it, 5 of which are inhabited. There are also 4 moons that support life, Three orbiting its large gas giant of Yorshma. (Click on planet name to find out more about it)
As regular as clockwork, every 2.867... days, the brightness of the star plummets to 30 percent of normal and back, the whole event (including recovery) taking only a few hours.
Algol has 7 planets orbiting it, 5 of which are inhabited. There are also 4 moons that support life, Three orbiting its large gas giant of Yorshma. (Click on planet name to find out more about it)
AU = Astronomical Units, Ey = Earth Years, Ed = Earth Days, Eh = Earth Hours